tear fluid, cell culture supernatant, other biological media
The Human Lacritin ELISA Kit is used for the quantitative measurement of human lacritin in tear fluid, cell culture supernatant, and other biological media.
- Upon receipt store all components at 4°C.
- Don't expose reagents to excessive light.
Intra-assay (Within-Run, n=4) CV=4.6-5.4%
Inter-assay (Run-to-Run, n=4) CV=2.4-8.5%
The limit of detection (defined as such a concentration of human lacritin giving absorbance higher than mean absorbance of blank* plus three standard deviations of the absorbance of blank: A blank + 3SD blank) is better than 32.4 pg/mL of sample.
Lacritin is a 12.3 kDa tear glycoprotein that is apically released from human lacrimal acinar cells during reflex tearing and can be detected in mixed reflex and basal human tears. Lacritin is produced by corneal, conjunctival, meibomian as one of the most eye-restricted genes. However it has been detected in a subpopulation of ductal cells in salivary glands, thyroid and mammary glands. Lacritin modulates lacrimal acinar cell secretion, promotes ductal cell proliferation, and stimulates signaling through tyrosine phosphorylation and release of calcium.
Since a decrease of tear lacritin was reported in patients with blepharitis and in contact lens-related dry eye, lacritin might play an important role in maintaining tear fluid and the ocular surface. In fact, ocular instillation of recombinant human lacritin stimulated basal tear flow in rabbits. Lacritin also promotes basal tear secretion by cultured rat and monkey lacrimal acinar cells and stimulates human corneal epithelial cell growth. Thus, lacritin appears to be a multifunctional eye-specific factor with a potential role in tear secretion and corneal epithelial renewal